stringT.py

s = "Python"

# ---------- INDEXING ----------
print(s[0])            # P       -> first character
print(s[-1])           # n       -> last character

# ---------- SLICING ----------
print(s[1:4])          # yth     -> start=1, end=4(exclusive)
print(s[:4])           # Pyth    -> start defaults to 0
print(s[2:])           # thon    -> end defaults to len(s)
print(s[::2])          # Pto     -> step=2
print(s[::-1])         # nohtyP  -> reverse string

# ---------- IMMUTABILITY ----------
# s[0] = 'J'           # ERROR: strings are immutable
print('J' + s[1:])     # Jython  -> create new string

# ---------- OPERATORS ----------
print("Py" + "thon")   # Python  -> concatenation
print("Hi" * 3)        # HiHiHi  -> repetition
print('P' in s)        # True    -> membership test
print('X' not in s)    # True    -> membership test

# ---------- ESCAPE CHARACTERS ----------
print("A\nB")          # A
                        # B       -> newline

print("A\tB")          # A    B  -> tab
print("A\\B")          # A\B     -> backslash
print("A\'B")          # A'B     -> single quote
print("A\"B")          # A"B     -> double quote
print(r"A\nB")         # A\nB    -> raw string

# ---------- FORMATTING ----------
name, age = "John", 25

print(f"{name} {age}")                 # John 25
print("{} {}".format(name, age))       # John 25
print("%s %d" % (name, age))           # John 25

# ---------- BUILT-IN FUNCTIONS ----------
print(len(s))          # 6        -> length
print(max(s))          # y        -> highest ASCII char
print(min(s))          # P        -> lowest ASCII char
print(sorted(s))       # ['P','h','n','o','t','y']

# ---------- CASE CONVERSION ----------
print(s.upper())       # PYTHON
print(s.lower())       # python
print(s.capitalize())  # Python
print("hello world".title()) # Hello World
print("PyThOn".swapcase())   # pYtHoN

# ---------- CHARACTER CHECK ----------
#Does every character satisfy this condition?
print("abc".isalpha())     # True
print("123".isdigit())     # True
print("abc123".isalnum())  # True
print("   ".isspace())     # True
print("my_var".isidentifier()) # True
print('ABCD'.isupper())   # True
print('abcd'.islower())   # True
print('5678'.isdigit())   # True
print("Hello World".istitle()) # True

# ---------- ASCII CONVERSION ----------
print(ord('A'))        # 65
print(ord('a'))        # 97
print(chr(65))         # A
print(chr(97))         # a

# ---------- SEARCHING ----------
print(s.find("th"))    # 2      -> returns -1 if absent
print(s.rfind("o"))    # 4      -> search from right
print(s.index("th"))   # 2      -> error if absent
print(s.count("o"))    # 1      -> occurrence count

# ---------- REPLACE ----------
print(s.replace("Py","My")) # Mython

# ---------- STRIP ----------
print(" hello ".strip())    # hello
print(" hello ".lstrip())   # hello_
print(" hello ".rstrip())   # _hello
# _ represents preserved space

# ---------- SPLIT ----------
print("a,b,c".split(","))   # ['a', 'b', 'c']
print("a b c".split())      # ['a', 'b', 'c']

# ---------- JOIN ----------
print("-".join(['a','b','c'])) # a-b-c

# ---------- PREFIX / SUFFIX ----------
print(s.startswith("Py"))   # True
print(s.endswith("on"))     # True

# ---------- ALIGNMENT ----------
print("Hi".center(10))      # '    Hi    '
print("Hi".ljust(10))       # 'Hi        '
print("Hi".rjust(10))       # '        Hi'
print("42".zfill(5))        # '00042'

# ---------- COMPARISON ----------
print("abc" == "abc")       # True
print("abc" < "abd")        # True
print("ABC".lower()=="abc") # True